BETA DOUBLING 66 HOURS ??

I went in for my first beta at 9DPT (last Thursday) and it was 64.

I went in Monday, 13DPT and my beta was 178. I go tomorrow for my third beta and im curious if anyone has had a similar experience and what your outcome was?

I had a miscarriage in March and my levels were almost tripling every 48 hours so I am guarding my heart this time. The clinic doesnt seem too concerned and said its doubling every 66 hours

My progesterone is 39.8 which is good - my MC in March my initial progesterone was low and my MC in 2024 my progesterone initially was low as well.